The present invention relates to security alarms and anti-theft devices and, particularly, to an improved sensor design which allows limited freedom of movement of a consumer item to which it is attached.
In recent years, retail and wholesale merchandisers have directed substantial attention to the nagging and costly problem associated with the theft and/or damage of costly display products on their premises. With the advent of smaller and more portable electronic apparatus, the ease with which pilferers and shoplifters can quickly and easily remove such goods from display cases and display racks has intensified. At the same time, the availability of new products, such as video cassette recorders, small portable radios and televisions, calculators and the like has skyrocketed, resulting in more and more valuable products being taken or tampered with. As locks and other security devices have become more sophisticated, so too have the individuals and methods for circumventing the operation of conventional security devices and, particularly, alarm sensing devices. The alarm system described in U.S. Pat. No. 5,172,098, to Leyden, has solved many of these problems. Some products, such as remote controls, are designed to be held and moved about. A sensor which can move freely with the product for a limited distance but returns the product and sensor to a set position when not being handled by a customer is optimal.
The above invention is specifically directed to overcoming the above problems in a novel and simple manner. The invention is particularly directed to use with remote controls but is not limited to this use.
According to the present invention, a retractable sensor is provided for use with an alarm system to prevent the theft of valuable products, such as video cassette recorders, small portable radios and televisions. The retractable sensor consists of a housing, a retraction device contained in the housing, a sensor having two states, 1) secured when attached to the product and 2) unsecured when detached from the product, and a multiconductor cable with one end attached to the sensor, then extending into the housing, cooperating with the retraction device and the second end extending out of the housing, the retraction device urging the sensor to the housing, yet allowing the sensor to be pulled from the housing when an external force is exerted on the sensor while maintaining a continuous electrical path from the first end to the second end of the cable.
Preferably, the sensor has an indicating device on its housing for displaying the state of the sensor. In a highly preferred form, the indicator is a light-emitting diode.
One embodiment uses a phone cord as the multiconductor cord.
Preferably the second end of the cable contains a connecting device to mate with an alarm system, such as the alarm system described in U.S. Pat. No. 5,172,098.
A preferred form of the invention has a retraction structure consisting of a spool mounted for rotation in the housing on which the multiconductor cable is wound and a device operatively associated with the spool for urging the spool in a direction to wind the cable onto the spool, yet permitting the unwinding of the cable when a user pulls the product, attached to the cable by the sensor, away from the housing.
With the above apparatus, the user can grasp and pull a product to a comfortable position. But if the user attempts to detach the product from the sensor, the alarm system detects this and warns the merchant.